X-Ray Repair Cross-Complementing Group 1 (XRCC1) Genetic Polymorphisms and Gastric Cancer Risk: A HuGE Review and Meta-Analysis

The authors performed a systematic review and meta-analysis of associations of the x-ray repair cross-complementing 1 gene (XRCC1) single nucleotide polymorphisms (SNPs) Arg194Trp, Arg280His, and Arg399Gln with gastric cancer risk, based on eligible studies retrieved from electronic databases for the period January 2000-December 2009. Ultimately, 12, 6, and 3 studies were found to be eligible for meta-analyses of Arg399Gln, Arg194Trp, and Arg280His, respectively. Regrouping was adopted in accordance with the most probably appropriate genetic models. Potential sources of heterogeneity were sought out. For overall gastric cancer, the pooled odds ratios for Arg399Gln, Arg194Trp, and Arg280His were 1.04 (95% confidence interval (CI): 0.90, 1.20; P = 0.572), 0.83 (95% CI: 0.68, 1.01; P = 0.059), and 1.18 (95% CI: 0.92, 1.50; P = 0.194), respectively. After stratification of the Arg399Gln SNP data by anatomic type (cardia vs. noncardia), the pooled odds ratio was 1.07 (95% CI: 0.84, 1.37; P = 0.568). The authors conclude that the 3 SNPs evaluated are not associated with risk of gastric cancer. The Arg399Gln SNP is not associated with the cardia type of gastric cancer. Evidently, the heterogeneity regarding the Arg399Gln SNP across studies is not explained by ethnicity, genotyping technique, sample size, or date of publication.